cat>cpp_preprocessor_variable.cxx<<EOF
#include <$$header>
DEFINED_PREPROCESSOR_VARIABLE=$$variable
EOF
SET_DEFINED_PREPROCESSOR_VARIABLE=`$CXXCPP cpp_preprocessor_variable.cxx | grep DEFINED_PREPROCESSOR_VARIABLE`
eval $SET_DEFINED_PREPROCESSOR_VARIABLE
$$variable=$DEFINED_PREPROCESSOR_VARIABLE